J/ApJ/887/268ivo://CDS.VizieR/J/ApJ/887/268doi:10.26093/cds/vizier.18870268CDSCalderone G.Boutsia K.Cristiani S.Grazian A.Amorin R.D'Odorico V.,Cupani G.Fontanot F.Salvato M.2022-08-09T14:04:53Z2021-02-19T06:39:56ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frquasarssurveysvisible-astronomyspectroscopyredshiftedinfrared-photometryphotometryintergalactic-mediumThe study of absorptions along the lines of sight to bright high-z QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, dark matter, primordial elements, reionization, fundamental constants, and general relativity. Unfortunately, the number of bright (i<~18) QSOs at z>~2 in the southern hemisphere is much lower than that in the north, due to the lack of wide multiwavelength surveys at decl. {delta}<0{deg}, hampering the effectiveness of observations from southern observatories. In this work we present a new method based on Canonical Correlation Analysis to identify such objects, taking advantage of a number of available databases: Skymapper, Gaia DR2, WISE, and 2MASS. Our QSO candidate sample lists 1476 sources with i<18 over 12400deg^2^ in the southern hemisphere. With a preliminary campaign we observed spectroscopically 69 of them, confirming 54 new bright QSOs at z>2.5, corresponding to a success rate of our method of ~80%. Furthermore, we estimate a completeness of ~90% of our sample at completion of our observation campaign. The new QSOs confirmed by this first and the forthcoming campaigns (QUBRICS survey) will be the targets of subsequent studies using higher resolution spectrographs, like ESPRESSO, UVES, and (in the long term) ELT/HIRES.2019ApJ...887..268Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/887/268CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)VII/286 : SDSS quasar catalog, fourteenth data release (Paris+, 2018)J/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)J/ApJ/819/24 : z>4.5 QSOs with SDSS and WISE. I. Opt. spectra (Wang+, 2016)J/AJ/153/107 : Australian Dark Energy Survey (OzDES) QSO cat. (Tie+, 2017)J/MNRAS/488/1035 : AGN UV luminosity function (Kulkarni+, 2019)J/ApJS/243/5 : The ELQS in the PS1 footprint (PS-ELQS) (Schindler+, 2019)J/ApJS/250/26 : Spectroscopic follow-up of the QUBRICS QSOs (Boutsia+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/887/268https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/887/268http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/887/268https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/887/268https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/887/268http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/887/268GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/887/268/table3 (List of SkyMapper sources in the candidate sample observed in our campaigns)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/887/268/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/887/268/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/887/268/table3?GETtext/xml+votable180.050000true8.9920833-20.09895830.005555555555555556Cone search capability for table J/ApJ/887/268/table4 (List of SkyMapper sources observed in our campaigns that are not in the final candidate sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/887/268/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/887/268/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/887/268/table4?GETtext/xml+votable180.050000true30.0677083-6.86918330.0055555555555555566/16787 16991 17035 17105 17525 18463 18500 18652 18704 18706 19104 24660 24666 24677 24768 24809 24870 24937 24967 25004 25229 25231 25270 25274 25324 25331 25334-25335 25374 25379 25435 25457 25478 25486 25546 25574 25632 25658 25720 25790 25792 25902 25984 25994 26291 26642 26748 26757 26770 26773 26843 26847 26859 26919 26960 27127 27138 27150 30924 30951 33353 33615 33684 34209 34697 34700 34719 34739 35627 35980 36601 36684 38399 38757 38890 40257 40294 40308 40829 40949 43759-43760 43891 43985-43986 43995 44204 44285 44608-44609 44653 44663 44724 44742 44760 44847 44925 45008 45163 45262 45279 45290 45335 45421 45543 45719 45777 45801 45876 45976 46025 46027 46228 46325 46473 46646 46789 46850 47005 47014 47537 47548 48193 48293 48493 48566 48641 48845 49012 49141-49142https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/887/268?format=asciiOpticalInfrareddefaultJ/ApJ/887/268/table3List of SkyMapper sources in the candidate sample observed in our campaignsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[175107/317598139] SkyMapper identifiermeta.id;meta.mainlongf_IDFlag on ID (1)meta.codecharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainDateDate of observation (UT)time.epochnullableimag[14.8/18.1] SkyMapper i-band magnitudemagphot.mag;em.opt.IfloatOTObject type ("QSO", "AGN", "STAR", "GAL" or "???" )src.classcharzspec[0.006/4.9]? Spectroscopic redshiftsrc.redshiftfloatnullableInstInstrument (2)meta.id;instrcharNoteNotemeta.notecharJ/ApJ/887/268/table4List of SkyMapper sources observed in our campaigns that are not in the final candidate sampleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[175107/317598139] SkyMapper identifiermeta.id;meta.mainlongf_IDFlag on ID (1)meta.codecharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainDateDate of observation (UT)time.epochnullableimag[14.8/18.1] SkyMapper i-band magnitudemagphot.mag;em.opt.IfloatOTObject type ("QSO", "AGN", "STAR", "GAL" or "???" )src.classcharzspec[0.006/4.9]? Spectroscopic redshiftsrc.redshiftfloatnullableInstInstrument (2)meta.id;instrcharNoteNotemeta.notechar